Preparation of cyclopentadienyl manganese compounds



- PREPARATION OF CYCLOPENTADIENYL MANGANESE COMPOUNDS N Drawing. Application July 24, 1957 Serial No. 673,768

1 Claim. (Cl; 202-46) This invention relates to the manufacture of organo metal carbonyl compounds and more particularly to the separation and recovery of cyclopentadienyl manganese tricarbonyl .compounds, and especially alkylcyclopentadienyl manganese tricarbonyls.

Cyclopentadienyl manganese tricarbonyl compounds have been found to be exceptionally efiective antiknocks for use in fuels, for spark plug ignition internal combustion engines. These compounds not only have exceptional etiectiveness as antiknocks but also many of these compounds, principally the liquid compounds, have auxiliary properties which make them entirely practical and desirable for commercial use. These auxiliary properties include high solubility in fuels, such as gasoline, and

thermo-stability either alone or in gasolines which makes these compounds entirely satisfactory for use under the widely varying conditions to which gasoline and other fuels are normally subjected. Possibly of even greater importance, these compounds do not tend to form any appreciable deposits on the engine pistons, valvesand spark plug surfaces and likewise are not abrasive tothe engine parts as are characteristic of iron compounds. A preferred method of manufacture of these cyclo pentadienyl manganese tricarbonylcompounds comprises reacting carbon monoxide with a bis(cyclopentadienyl) manganese compound, e. g. bis(methylcyclopentadienyl) manganese. In this reaction, only one of the two cyclopentadienyl radicals in the bis-compound is used in forming the product. lost as byproduct, normally polymerizing to a soft, sticky material. This byproduct causes difficulty in subsequent recovery of the cyclopentadienyl manganese tricarbonylas hereinafter described. 7

The bis(cyclopentadienyl) manganese compound is normally made by reaction of a cyclopentadienyl sodium compound or other alkali metal compounds with a manganous chloride or other salt. Sodium chloride is formed as a byproduct, two moles per mole of the bis-manganese product. The carbon monoxide is normally added directly to thisreaction product, forming a second reaction product of thedesired cyclopentadienyl manganese tricarbonyl. This second reaction product also contains many impurities, including the polymer, noted above, sodium salts, unreacted manganese salts and the like which makes product separation and materials handling extremely difficult. These impurities in most cases are present even in greater quantities than the desired product. I

It is accordingly an object of this invention to provide a high ultimate yield of product and which provides easy- The other cyclopentadienyl radical is United States Patent 0 advantages of this invention will be apparent for the following description and appended claims.

These and other objects of this invention are accomplished if the cyclopentadienyl manganese tricarbonyl compound is steam distilled from the reaction product while maintaining the byproduct in a fluid state in a liquid hydrocarbon, particularly aromatic hydrocarbons, having at least 12 carbon atoms. More specifically, the crude reaction mixture, Which normally contains about equal quantities or" the desired cyclopentadienyl manganese tricarbonyl product and impurities, such as organic polymer and salts, is suspended in the high boiling liquid, preferably in contact with a suitable volume of Water which is immiscible with the high boiling liquids defined above. Steam is then injected into the liquid suspension or solution to distill the desired product as a water azeotrope. During the steam distillation, the system is preferably agitated so as to maintain essentially a homogeneous mixing of the immiscible phases. Normally, it is preferred to remove any solvent from the crude reaction product by a straight distillation, vacuum or pressure,

either prior to or after addition of the high boiling liquid.

- The present recovery process is particularly desirable due to the essentially complete recovery of the desired product. The large quantities of polymeric and inorganic purities are maintained in a highly fluid state, the organic.

phase normally being dissolved or suspended in the high boiling liquid and the inorganic phase being.di ssolved in values can be converted to additional manganese salt ing liquid is the unexpected reduction in foaming and frothing which normally accompanies steam distillation of the crude reaction mixture in the absence of such high boiling liquids. This problem is very serious in large scale commercial operation since it materially re I duces the throughput capacity of the process equipment.

Also, the use of high boiling liquids in accordance with this invention materially increases the steam efliciency during the'recovery operation. I

'1 The foll wing are typical examples of the present invention which are presented for the purpose of illustrating the beneficial characteristics of the present process. All units in the following examples are given in parts by weight.

EXAMPLE I A crude reaction product (1310 parts) prepared as defined below was diluted with 393 parts of a liquid consisting essentially of methylated naphthalenes which is commercially marketed as a light phenol extract and obtained asthe bottornsof a distillation of the product recovered obtained from steam cracking of oil gas. This material has an initial boiling point of about 270 C. This mixture was then vacuum distilled at a temperature of C. in distillation equipment having a ten plate column maintained at 50 mm. mercury pressurer-A 5:1

The manganese reflux ratio was employed and the mixture in the pot was continuously stirred. 540 parts of diethylene glycol dimethyl ether were removed asdistillate. 750 parts of water were .thenadded to thesolvenefree reaction;

mixture in a steam still and steam wasinjected (40 lbs./ sq. in. atm. pressure). An azeotmpe' distilled at a I temperature of. 100' to 104 C. which was ollected and.

and the methylated naphthalene phaseand 'both were" highly fluid and steam still. d ,c

The manganeseco'mpound, recovered as above is then subjected to" fractionation and 'this purified product is thereafter blended withgasoline. The following Table I presents data showing. the octane increase of a commercial gas'o'lineh'aving an initial boiling point of 94 F. anda finalboiling point "of 390 F. [The antiknock value of the fuelas determined by the ratings are given in octaneTnu'mbersfor figures below 100 and in Army- Navy performance numbers for values above 100. The method of determining performance numbers is explained in-the booklet Aviation Fuels and their Effect on Engine Performance, 'NAVAER-06-5-50l, USAF T. O. No. 06- 5-54, published in 1951. '1

Table I A could be readily discharged, from the V CuHflVIn g. metal/gal. Octane Rating 'The crude-reaction mass treated above was: prepared reacting 1448} parts of sodium metal with 1835 parts of methylcyclopentadiene in 708 parts of diethylene glycol dimethyl ether. This reaction was conducted at a temperature of 111 C. The system was agitated to disperse the sodium prior to reaction with the methylcyclopentadiene. To this reactionmixture was added 708 parts of manganouschloride andthe temperature was raised to about 126 C. while agitating the reaction mixture. After completion of this' reaction, carbon monoxide was added (305.lbs./sq. in.) and thetemperaturewasraised to 193 C. Vigorous. agitation was employed throughout this reaction. This crude reaction mixture, protected against exposure to airtor moisture, was then treated to recover the methylcyclopentadienyl manganese tricarbonyl in accordance with the above procedure.

' EXAMPLE 11 Example I was repeated except that 383 parts of a commercial product, Enjay atoniatici 9,700, manufactured. by .Esso. StandardjOi] Company wa sj used in place of the .methyIatQdlIIaPht. l fofEJxa i commercial product. is. predominately aromatic hydrlocarbons containing both benzene and naphthalene derivatives and has an initial'boiling point of about 1455C. at 20 mm. mercury pressure, The methylcyclopentadienyl manganese tricarbonyl product was recoveredin cssential quantitative yields and the distillate residue was highly fluid and could be readily dischargedfromf the steam still. Due to the somewhatlower boiling point of the Enjay material, a small amountof the high boiling liquid was recovered with the product but this ma: terial could thereafter be separated from the product by fractionation. 1... 'E M LB .1;

Example I Was'repeated except-that tlie"d'iethylene glycol dtmethyl ether solvent was vacuum distilled prior to the addition of the water and the methylated naphthalene liquid. Beginning with 1113 parts of reaction product, 437 parts of the solvent were recovered. Also, steam distillation was begun prior to the addition of the methylated naphthalenes. About 250 parts of the methylcyclopentadienyl' manganese tricarbonyl were recovered and then 334 parts' of the methylated naphthalene was added to the partially distilled reaction product. The remaining. methylcylopentadienyl manganese tricarbonyl product '(60 parts) where thereafter "steam distilled and recovered. Recovery of the product from the crude mixture was essentially complete and the distillate residue was highly fluid and could be readily removed from the process equipment.

EXAMPLE IV 604 partsiofsolvent were removed during vacuum distillati on and 265 parts of the product were steam distilled of a 'total' of 318 parts prior to the addition of the methylated naphthalenes. .f

' .EXAM LE v1 Example I is repeated except that cyclopentadiene isreacted with a molar equivalent of potassium metal in a dispersion in-min'eral oil,"'1': l' w'eight' ratio of metal and oil. "The reactioii'is conducted at50 C. Manganous acetate in a 1:2 mole ratio is then added to this reaction product and reacted at a temperature of C. This. second reaction mixture is there'after'carbonylated at. C., using 600 p. s. i. g. carbon monoxide pressure. The reaction mixture, protected against air and moisture, is then distilled in accordance with the pro-' cedure of Example I, using ethylated naphthalene as the high boiling liquid. The cyclopentadienyl manganese tricarbonyl product is recovered in essentially complete yield and the steam distillation residue is highly fluid and can be readily discharged from the steam still.

' EXAMPLE v11 Example I is repeated except: that indene is employed in placeof the r'nethylcyclope'ntadiene and diethylene'gly'-' col dibutyl ether is'used as the solvent. About3 times the weight of solvent isuse'd in this run. Man'ganous bromide is reactedv instead of manganous chloride with the first reaction product. The indenyl manganese tricarbonyl product. is recovered in accordance withithe procedure-in Exarnple l. except that triethyl benzene is used as the high boiling liquid;

EXAMPLE V111" Example I is repe ted except that diethylcyclopentadiene-is reacted with 'the sodium in cyclohexylamine. Manganous iodide is.used toreact with the diethylcyclopentadienyl sodium. -Anthracene is employed as the high boiling solvent during the steam distillation. Similar results are obtained.

. EXAMPLE 1x Example I repeated except that lithium is used as the alkali metal and a 50 50 weight by weight mixtureof biphen'y'lf and bipheh'yl tether is' employedin the steam 'distilla'tion'; The formationnf thdm'ethyl t -ctopemaaien i lithium compound is carried out at 200 C. and the methyt 'cyclopentadiene dimer is fed directly to the reaction mixture. Essentially quantitative productrecovery is obtained and'the product residue remains ma fluid state.

EXAMPLE X EXAMPLE XI Example I is repeated except that phenyl naphthalene is used. In this example only about 250 parts of water are added prior to the steam distillation.

EXAMPLE XII Example I is repeated except that a low polystyrene polymer having an initial boiling point of about 275 C. is employed in place of the methylated naphthalene. The product is essentially completely recovered and the steam still residue is highly fluid and can be easily drained from the steam still.

EXAMPLE XIII Example I is repeated except that reaction "mixture contains indenyl manganese tricarbonyl instead of the methylcyclopentadienyl compound and a low butadiene' polymer is used as the high boiling liquid. Similar results are obtained;

When the above examples are repeated using different reflux ratios, e. g., 1:1, 4:1 and :1, similar results are obtained. Either superatmospheric or subatmospheric pressures can be used in the above examples with generally equal results, e. g. 0.5 atmosphere, 10 atmospheres and 30 atmospheres. In the straight distillation of solvent somewhat better separations are obtained with pressure operations.

The following Table II presents in tabular form Examples XIV to XVIII inclusive. trate the process of this invention using different types of reaction products, solvents, and high boiling liquids for suspending the reaction product residue. The reaction products treated in Examples XIV and XV are prepared similar to the procedure illustrated in Example I except that cyclopentadiene and indene are employed instead of methylcyclopentadiene. In all of these examples, essentially complete recovery of the desired manganese compound is obtained and the residue is highly fluid and can be readily discharged from the distillation equipment.

liquidcan range fromabout 0.01 to about 10 parts/part of the cyclopentadienyl manganese tricarbonyl compound These examples illusavailability. as byproducts, particularly from the petroleum refining industry. The most desirable aromatic hydrocarbons are the naphthalene type, particularly the alkylated naphthalenes, either as pure compounds or as mixtures with benzene derivatives or anthracene derivatives. Typical examples of suitable aromatic hydrocarbons are diisopropyl benzene, triisopropyl benzene, tributyl benzene, diphenyl, terphenyl, naphthalene, methylated naphthalenes, either mono-.or polysubstituted, anthracene, including the alkyl derivatives of anthracene such as the mono-, dior higher methyl substituted anthracenes, ethyl anthracenes, dibutyl anthracenes, and the like. In some cases, aromatic hydrocarbons which contain other substitutions, such as halogen substitutions, act similarly to hydrocarbons and can be considered equivalents. Examples of these are the chlorinated benzenes and naphthalenes. Other hydrocarbons suitable for use in this invention are dodecane, pentadecane, octadecane, octacosane and the like.

The particular high boiling liquid to be preferred in this invention depends somewhat on the product to be In general, the liquid should have a boiling recovered. point from 0-150" C. degrees above the boiling point of the product and preferably from '50-100 C. degrees. With liquids having lower boiling points, an excessive quantityof liquid is removed with the product and must be separated by fractionation or similar techniques: Higher boilingpoint liquids do not adequately flush or purge the product from the distillation equipment.

The concentration of the high boiling, water-immiscible in the crude reaction mixture. A more preferred concentration is from 1 to 5 percent. In general, it is preferred to use as low a concentration as is possible while still maintaining a fluid system under processing conditions. This is particularly true when it is desired to dispose of the fluid residue by burning, using the high boiling liquid as a source of fuel. Higher concentrations can be used although there is no particular advantage from a processing standpoint and actually greater quantities are disadvantageous, due to reduction of product throughput in the recovery equipment and increased costs of using and handling greater volumes of material.

The quantity of water to be added to the reaction mass prior to the steam distillation is not critical and, in fact. its addition can be eliminated, if desired. Normally, however, a weight of water ranging from about /3 to 5 times the weight of the reaction mass is used. Usually, the reaction mixture is suspended in from about one-half to about equal quantities of water before beginning the steam distillation.

Table II Example Reaction Product Solvent High Boiling Liquid Parts R. P./ Steam, Inor anic H. B. L. p. s. i. g. Salt XIV cyglopelntadienyl manganese tricartetrahydroiuran. mineral oil 1.0 40 NaCl.

ony V indenyl manganese trlcarbonyl benzene. tetraoosann 0. 5 5 K Br. XVI methylcyclpentadienyl manganese dimer (MOP) ethyl naphthalene 4.0 100 lithium trlearbonyl. acetate. In II do diethylene glycol dibuty1naphthalene 2. 0 NaCl.

dimethyl ether. XVIII do -do methylated anthracene" 0.9 20 NaCl.

1 Weight of product in the crude reaction product/weight of high boiling liquid.

A wide variety of high boiling water immiscible hydrocarbon liquids can be employed in the process of this invention selected from the group consisting of hydrocarbons, particularly aromatic hydrocarbons, having at least 12 carbon atoms and usually not greater than 30 carbon atoms and certain ethers and esters, such as are listed above. The aromatic hydrocarbons are by far the most preferred due to the unexpected fluidity of the distillate residue in these liquids and due to their low cost and The present process is suitable for recovery of a wide variety of cyclopentadienyl manganese tricarbonyl compounds and is particularly desirable for recovery of such compounds having cyclopentadienyl radicals containing from 5 to 13 carbon atoms. These latter compounds have molecular weights up to about 315. Typical examples of cyclopentadienyl manganese tricarbonyl compounds which can be recovered in accordance with this invention are cyclopentadienyl manganese tricarbenyl,

. 7 .l a methylcyclopentadienyl manganese tricarbony, I manganese tricarbonyl, ethyl cyclopentadienyl manganese tricarbonyl, phenyl methylcyclopentadienyl manganese tri'c'arbonylandthelike. l I a Thev above cyclopentadienyl mangar'lese, t ricarbonyl compounds can be prepared frorn corresponding bis (cyclopentadienyl) alkali metal compounds byjreaction with carbon monoxide, For example, 1 Cyclopentadienyl manganese tricarbonyl is preparedvbylhe reaction ot carbon monoxide with bis(cy clopentadienyl) manganese.

Likewise, the methylderivative,,;i. e. methylcyclopentadienyl manganese ,tricarbonyLi is prepared by reacting carbon monoxide with bis(methylcyclopentadienyl) manganese. Thus, corresponding lcy clopentadienyl manganese tricarbonyl'compounds, can? be prepared from bis hy Y a i n' ganese, bifln ctyl. W9 pentadienyl) manganese, hisfindenyl) manganese, bis (fluorenyl) manganeseand the like. V r v I The above compounds can be pr epared by a number of known processes and, in general,' are' synthesized in three separate steps. An alkali metal (e, g sodium, potassiurn or lithium) cyclopentadienyl compound is prepared by reaction of the corresponding alkali metal with thecyclopentadien e hydrocarbon in a suitable solvent, such as a hydrocarbon or ether, e. g. toluene, diethylene glycol dimethyl ether or tetrahydrof uran. This reaction is conducted with agitation at a tem-perature of-from to 250 C preferably above 1 00t,C., using either the cyclopentadiene monomer or dimer, This reactionrnixture is then reacted with :a mauga nous salt Suitable manganous salts are halides, such as the chloride or a an i bromide, m'angs su's' sulfate or organic salts, such as the. acetate ln generahthis reaction is conducted in ether type solvents; such as those discussed above, at a temperature of to 250 C., usually from to 175 C. This second reaction product is then reacted with carbon monoxide usually atpres sures of from 100 to 500 lbs/sq. in, althoughbbth lower and higher pressures can ube use dnaThis carbpnylat ionreaction is normally conducted at temperatures'of from to 250 C. using agitation. J a

The crude reaction mixture as prepared above should be protected from contactof air'or moisture since materially greater difficulty is encountered in the, steam distillation after prolonged texposilre of the crude mixture to either air or moisture, 5 Normally, the crude mixture is maintained under an inert atmosphere prior to distillation or the crude mixture is fed directly to the distillation equipment in a closed system.

In a process tor "produicirrg cyclop'entadienyl manganese tricarbonylllcompounds in which a cyclopentadiene compound is reacted with an alkali metal; the reaction prodnot is thereafter reacted with a'manganous salt and the product of the latter reaction is then reacted with carbon monoxide in the presence or a solvent, the improvement comprising steam distilling said cyclopentadienyl manganeselvtricarbonyl compound in the presence of from about Q .O:1 't o .about lO parts per partof said cyclopentadienyl urnang'an ese, t ricarbonyl c ompound of a hydrocarbon liquidhaving at least 12 carbon atoms.

: Noreferences cited. 

